Ferroskutterudite is an iron-rich member of the skutterudite group, characterized by its metallic silver-white color and cubic habit. Collectors typically find this rare arsenide mineral in cobalt-silver hydrothermal vein deposits alongside other arsenic-bearing minerals.

Hardness

6-6.5

Mohs

Luster

Metallic

Transparency

Opaque

mineralrareSkutterudite Group family

Ferroskutterudite

Hardness: 6-6.5
Luster: Metallic
Transparency: Opaque

No image

Is this ferroskutterudite?

4-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch ferroskutterudite with a known reference. Ferroskutterudite sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
2
Read the luster
Hold the specimen under a strong light. Luster: metallic.
3
Match the color range
Compare against the expected color range: tin white.
4
Look at form & habit
Crystal system: cubic. Typical habit: granular.

Often confused with

Ferroskutterudite vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside ferroskutterudite

Minerals reported to co-occur with ferroskutterudite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: FeAs₃
Mohs hardness: 6-6.5
Density: 6.7-6.9 g/cm³
Colors: Tin white
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Granular
Cleavage: Perfect, probably on {02̄1}
Rarity: Rare
Uses: Collector
Host rock: In hydrothermal dolomite-calcite veins and apophyllite-anhydrite-carbonate veins in a magmatic hydrothermal Co-Ni antimonide-arsenide deposit

Where rockhounds find ferroskutterudite

Classic worldwide localities

Noril’sk ore field, Russia

Field-hunting tip

Where it forms: In hydrothermal dolomite-calcite veins and apophyllite-anhydrite-carbonate veins in a magmatic hydrothermal Co-Ni antimonide-arsenide deposit. If you start seeing wurtzite, sphalerite, galena in float, you are in the right ground. Typical habit: granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ferroskutterudite?+

Mohs hardness is 6-6.5. Luster: metallic. Common colors include tin white.

Where is ferroskutterudite found?+

Notable localities include Noril’sk ore field, Russia.

Is ferroskutterudite safe to handle?+

Ferroskutterudite contains arsenic and calls for real care. Contains arsenic. Handle with care, wash hands after handling, and avoid dust inhalation or ingestion.

What rocks look like ferroskutterudite?+

Ferroskutterudite is most often confused with Skutterudite, Arsenopyrite, Cobaltite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with ferroskutterudite?+

Ferroskutterudite commonly co-occurs with Wurtzite, Sphalerite, Galena, Chalcopyrite, Pyrrhotite, Cubanite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ferroskutterudite form in?+

Where it forms: In hydrothermal dolomite-calcite veins and apophyllite-anhydrite-carbonate veins in a magmatic hydrothermal Co-Ni antimonide-arsenide deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ferroskutterudite used for?+

Ferroskutterudite is used in collector.

Find ferroskutterudite on the map

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